Relationships between Median Nerve and the Pronator Teres Muscle in the Cubital Region: Anatomic and Clinical Implications

DOI : 10.4067/S0717-95022015000400042

Riveros, A.; Olave, E. & Sousa-Rodrigues, C.

Summary

Intense muscle activity of the forearm generates the need to describe the possible sites of compression of the peripheral nerves of the upper limb. For the median nerve one of the most prevalent sites of nerve entrapment is when the nerve travels within the carpal tunnel. To this we must add the potential compression of the nerve when it passes through the heads of the pronator teres muscle (PT). This compression is characterized by paresis of the wrist flexor muscles or some of the thenar, signs which can add to numbness and pain in the hand. The aim of this study was to describe the relation of the median nerve with the PT muscle. Thirty formolized forearms of adult Brazilian individuals were used. It was found that in 40% of cases the median nerve crossed the ulnar head PT muscle. In one case the ulnar head was absent. Due to this, the median nerve passed posterior to the humeral head of this muscle. The clinic that develops from compression syndrome at this level is directly linked to the distribution of the branches that the nerve presents proximal to the site of compression. Associated with these findings, it is vital for optimal diagnosis of the compression of median nerve to rule out compression of this nerve in proximal sites to the carpal tunnel.